Image Processing with Cats and Scrimage - Scala 3

ImageTransformer.scala

/**
libraryDependencies += "commons-io" % "commons-io" % "2.10.0",
libraryDependencies += "com.sksamuel.scrimage" % "scrimage-core" % "4.0.20",
libraryDependencies += ("com.sksamuel.scrimage" %% "scrimage-scala" % "4.0.20").cross(CrossVersion.for3Use2_13),
*/

import cats.effect.{ExitCode, IO, IOApp}
import com.sksamuel.scrimage.ImmutableImage
import com.sksamuel.scrimage.nio.PngWriter
import java.io.File
import java.net.URL
import org.apache.commons.io.FilenameUtils
import scala.jdk.CollectionConverters.*

enum SIZES(val pixels: Int):
  case THUMBNAIL extends SIZES(160)
  case MEDIUM extends SIZES(720)
  case LARGE extends SIZES(1440)

object ImageTransformer extends IOApp:

  def transformImages(image: ImmutableImage) = IO {
    SIZES.values.toList.filter(_.pixels <= image.width).map { size =>
      image.scaleToWidth(size.pixels)
    } :+ image
  }

  def saveImages(fileName: String, images: List[ImmutableImage]) = IO {
    images.foreach { image =>
      image.output(
        PngWriter.MaxCompression,
        new File(
          s"/Users/username/Downloads/$fileName-${image.width}.png"
        )
      )
    }
  }

  def processImage(link: String): IO[ExitCode] =
    for {
      url <- IO(new URL(link))
      fileName <- IO(FilenameUtils.getName(url.getPath()))
      inputStream <- IO(url.openConnection.getInputStream)
      image <- IO(ImmutableImage.loader().fromStream(inputStream))
      tags <- IO(image.getMetadata.tags.toList)
      scaled <- transformImages(image)
      _ <- saveImages(fileName, scaled)
    } yield ExitCode.Success

  def run(args: List[String]) = processImage(
    "https://some.url.com/products/8675309_0.jpg"
  )